This invention relates to a technique for assuring that a route advertisement made by a customer remains accurate to assure that packets inbound to the customer on an advertised route are received.
The tremendous popularity of the Internet has led to a surge in data communications traffic both on the Internet itself, and on connecting networks. Consequently, many Internet Service Providers (ISPs) that provide access to the Internet, such as ATandT Worldnet, have themselves become larger, offering more available routes. With more routes available through an ISP to a given customer, the likelihood of a blocked route impairing transmission is reduced.
In many instances, a customer served by a particular ISP will advertise, (i.e., notify) senders of data of available routes through the customer-servicing ISP so that inbound data from a sender will reach the customer. Once a customer advertises a particular route, then that route should remain available without modifications by the customer-servicing ISP as well as other ISPs routing traffic thereto. Modifications made to an advertised route will likely cause inbound packets destined to a customer across that route to miss their intended destination.
Thus, there is a need for a technique assuring that route advertisements by a customer appear faithfully beyond the customer-servicing ISP to other ISPs without modification.
Briefly, in accordance with a preferred embodiment of the invention, there is provided a method for verifying the addition of a newly provisioned customer route as well as withdrawal of a previously provisioned route. The method commences upon receipt at a route provisioning system of new route information from a customer or upon a request to withdrawal of an existing advertisement. Upon receipt of a new route advertisement request, the new route is validated, and if unable to be verified is then rejected. (Generally, there is no need to verify withdrawal of an existing route although validation of the customer seeking withdrawal may prove useful.) Thereafter, the new route (or the withdrawal of an existing route) is entered into an official routing database and the information is thereafter made available both to the customer-servicing ISP as well as external ISPs. Finally, a check is made of all ISPs that the new route address (or withdrawal of the old address) is effective.